Modified soil-filled revetment

ABSTRACT

Soil-filled barriers, normally filled with heavy equipment, can be made quickly effective against small arms fire by modifying each cell of a barrier line (wall) with internal closeable gates that allow users to manually shovel fill a small arms security position in 65% less time than manually filling a standard barrier. Select embodiments of the present invention include gates that are inexpensive and lightweight compared to alternatives and readily fielded, in some instances as a field expedient modification. In select embodiments of the present invention the gates may be integrated into fielded conventional barriers, including employing field expedient means, as well as incorporated into production lines of new barriers specifically for use by light military units that operate in restrictive terrain.

STATEMENT OF GOVERNMENT INTEREST

Under paragraph 1(a) of Executive Order 10096, the conditions under which this invention was made entitle the Government of the United States, as represented by the Secretary of the Army, to an undivided interest therein on any patent granted thereon by the United States. This and related patents are available for licensing to qualified licensees. Please contact Phillip Stewart at 601 634-4113.

BACKGROUND

Soldiers are vulnerable to enemy attack during the setup of combat outposts in restricted terrain. Junger, Sebastian and Tim Hetherington, Restrepo documentary of the 173^(rd) Infantry Brigade in the Korengal Valley (http://www.youtube.com/watch?v=mKPULvGmz3U). Minutes 19:00-20:00 detail dangers encountered during combat outpost setup. Soil-filled revetments 10, such as Hesco Mil 1 Bastions, work extremely well in this role. They are meant to be set up around a base and filled in with heavy duty loaders as shown in FIG. 1. FIG. 2 (Prior Art) depicts Hesco Mil 1 Bastion® cells 10 being emplaced from a collapsed transport configuration. The Hesco Mil 1 Bastion® cells 10 collapse flat for efficient transport.

Soil-filled revetment cells 10 used by light units frequently have dimensions of 3 ½′ by 3 ½′ by 5′ height. When filled with soil, the cells 10 stop small arms fire and provide significant protection against blasts and limited protection against vehicle-borne improvised explosive devices (IEDs). An inherent problem with soil-filled revetments 10 is the unavailability of heavy equipment to fill them due to restrictive terrain or logistical issues. Users must fill these cells 10 by shovel over an extended period of time, leaving them exposed to hostile fire.

To provide quicker protection to users setting up security posts in restricted terrain, high-tech options were investigated to include spider silk liners as well as currently produced ballistic foams, steel foams, and the like. Each option was either prohibitively expensive, too heavy, immature technology, or a combination of these.

Refer to FIG. 1 (Prior Art). A common article used for defensive positions is the Hesco Mil 1 Bastion® cell 10, composed of a large quadrilateral (box-like) bottomless section of chain fencing and reinforced fabric for containing filler 11 such as sand or native soil. The process of filling these revetments is time consuming without access to heavy equipment 12. Soil-filled cells 10, such as the Hesco Mil 1 Bastions® cells, can be made quickly effective against small arms fire by modifying each cell 10 with internal closeable gates 31 (FIG. 3) that allow users to shovel fill a security position protected from small arms in 65% less time than completely filling a standard cell 10, such as a Hesco Mil 1 Bastion® cell 10. The gates 31 are inexpensive and lightweight compared to alternatives being considered, and readily fielded. The gates 31 may be integrated into fielded cells 10 of the Hesco type as well as incorporated into production lines for future use by security units that operate in restrictive terrain or must deploy without heavy equipment.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a photo of prior art conventional soil-filled cells” being filled by large mechanical loaders.

FIG. 2 is a photo of the prior art conventional soil-filled cells of FIG. 1 as they are being deployed from their folded transport configuration.

FIG. 3 is a photo of an embodiment of the present invention from a top profile view with a gate of select embodiments of the present invention partially open.

FIG. 4 is a photo of an embodiment of the present invention from a top profile view with the gates of select embodiments of the present invention closed.

FIG. 5 is a photo of an embodiment of the present invention from a top profile view with the gate of select embodiments of the present invention closed and the “quick-fill” sections filled with soil.

FIG. 6 is a photo of a spacer element made as a field expedient element for select embodiments of the present invention, the element cut and formed from vertical connector bars used for joining conventional soil-filled cells in a barrier line.

FIG. 7 is a photo of a user disconnecting a retaining spring of a conventional soil-filled cell as may be used in closing the gates of select embodiments of the present invention.

FIG. 8A depicts a line of barrier sections that can be modified in accordance with select embodiments of the present invention.

FIG. 8B is the line drawing of FIG. 8A marked for modification in accordance with select embodiments of the present invention.

FIG. 8C is the line drawing of FIG. 8B as modified in accordance with select embodiments of the present invention.

FIG. 9 depicts one alternative to establishing the material needed for making the gates of a field expedient version of select embodiments of the present invention.

FIG. 10 is a photo of users filling the “quick fill” sections from the friendly side of a revetment.

FIG. 11 is a photo showing a vertical profile of the side of FIG. 10 after filling just the “quick fill” sections.

FIG. 12 is a photo showing a vertical profile of a test setup of the partially filled cells of FIG. 11 from the hostile side in which it is apparent to the viewer that the cells are not filled on the hostile side.

DETAILED SPECIFICATION

Refer to FIG. 3. At Picatinny Arsenal, a gate 31 isolated a “friendly-side volume” 42 (FIG. 4) on the friendly, or protected, side of the Modified Soil-Filled Revetment 30. The modified revetment was tested using a thickness of soil 11 in the friendly-side volume 42 of approximately one foot. This stopped all rounds fired from an AK-47 (7.62×39), a 7.62×63 sniper rifle and the Dragunov sniper rifle (7.62×54) as well as bursts using the FN M240 machine gun (7.62×51 NATO). In actual use, after the gated volume 42 is filled and a security position effective versus small-arms thus achieved, the remaining (“hostile-side”) volume 43 (FIG. 4) within the modified revetment is filled to achieve nominal blast protection.

Testing of projectile penetration in sand was conducted using sand contained within a wooden box fabricated of individual sections stacked horizontally in a line one section wide when viewed from one end. Each section comprises ½″ drywall front and rear “walls” (retainers for the sand) containing a fill of sand establishing a depth of six inches of sand when viewed from one end. A single section of six inches of sand was sufficient to stop projectiles at or before the first section's rear drywall when fired from rifles of caliber 5.56 mm M193 Ball (.223 NATO) and 7.62×51 mm as well as from pistols of caliber 9 mm and .45ACP using ball ammo. The U.S. Army recommends one foot thickness for barriers against small arms fire. The Sands O' Truth, [Cited 2010 Oct. 18], www.boxotruth.com/docs/bot7_2.htm and personal interview with Dr. Paul Mlakar, United States Army Corps of Engineers, Nov. 9, 2010.

Investigation of a way to modify existing soil-filled cells 10 led to a field expedient method. By dividing each 3 ½′×3 ½′×5′ volume of a cell 10, such as a Hesco Mil 1 Bastion®, into a “quick-fill” volume 42 of 1′ ×3 ½′×5′ and a “2^(nd)-fill” volume 43 of 2 ½′3 ½′×5′, the smaller quick-fill volume 42 may be filled quickly to provide security from projectiles of small arms and the 2^(nd)-fill volume 43 filled as time and hostile action permit.

Refer to FIG. 8. By disassembling one cell 10 and taking the lateral sections 15 to modify other conventional soil-filled cells 10, such as Hesco Mil 1 Bastions®, one may create modified revetment cell 30 in the field. Using existing material from lateral panels 15, gates 31, fitted at a specified distance, d, from a lateral panel are able to be configured as shown in FIGS. 3 and 8C.

The process allows gates 31 to be fabricated onsite by removing joining springs 13 and cutting the fabric of the lateral sections 15 down the middle and attaching each half inside nearest friendly side of a conventional soil-filled cell 10, such as a Hesco Mil 1 Bastion®. The material of the cannibalized panel 15 is cut to facilitate folding the gate against a side of the cell 10 for transport and storage as well as to allow initial filling of the entire cell 10 if heavy equipment 12 is available immediately upon deployment. Refer to FIG. 9. Attachment of the material cut from a conventional soil-filled cell 10 is done at points 81 and assembled after cutting as shown in FIG. 9. By so doing, a user creates a gate 31 that is quickly deployable within a conventional soil-filled cell 10, such as a Hesco Mil 1 Bastion®, to absorb small arms fire while also retaining portability of the modified revetment 30.

FIG. 4 shows the gates 31 in the closed position. A flip-up brace 41, such as a metal connector, is also visible in one of the friendly-side sections 42, installed to manage the bulging of the side sections when filled and to maximize the top area of the friendly-side sections 42 as they are being filled.

A loose brace 41, as may be used in select embodiments of the present invention, is shown in FIG. 6. That brace 41 was cut from the rods that come standard for connecting sets of Hesco Mil 1 Bastion® cells 10 together. One end of the brace 41 is permanently clamped around one of the gate sections 31 about one foot from the top of the gate 31. When the gate 31 is not in use it hangs vertically against the gate 31. Once the gates 31 are closed, the other end of the brace 41 is pushed from the inside of the barrier 30 through a slit in the material of the main wall of the barrier 30 and affixed over the outside wire fencing 14 of the barrier 30.

FIG. 7 shows the spiral rod 13 as it is being rotated into place to connect gate sections 31 (a process that takes under a minute). Spiral rods 13 are part of the standard assembly of protective barriers, such as a Hesco Mil 1 Bastion®, permitting flexible joints and a strong connection. During testing the gates 31 were connected to the main frame by wire, although alternative means known in the art, such as zip ties, would be suitable.

EXAMPLE

Refer to FIGS. 8 and 9. Using select embodiments of the present invention a field expedient wall of modified soil-filled cells 30, as modified from conventional soil-filled cells 10, such as Hesco Mil 1 Bastions®, may be configured onsite by a user by employing the following steps:

-   1) Erect a barrier line of conventional soil-filled cells 10, such     as Hesco Mil 1 Bastions®. -   2) Obtain materials for constructing gates 31 in the individual     cells 10 of the barrier line by:     -   a) Separating one cell 10 from others by first bending the         “joining” springs 13 at the joints attaching lateral panels 15         of one cell 10 to another.     -   b) Unscrewing each joining spring 13 by turning it up out of its         fitted position to separate lateral panels 15 from end panels         17.     -   c) Cut fabric comprising the lateral panels 15 so that it         divides the panels 15 approximately in half.     -   d) Insure sections from a particular panel 15 are paired         together for each subsequent gate 31. -   3) If modifying a recently un-attached cell 10, reattach joining     springs 13 to main cell 10. -   4) If modifying a cell 10 in an existing barrier line, unscrew the     joining spring 13 at one joint 16 to gain easy access to the     interior. -   5) Deciding the distance, d, that the gates 31 should be from the     lateral side (lateral panels 15) and marking a number of points in a     vertical line on each of the appropriate end panels 17 at that     distance for connecting each of the two sections (fabric and hinged     fencing 14) comprising the gate 31 to the end panels 17. The U.S.     Army standard distance for small arms protection using sand or other     soil is twelve (12) inches. Thus, in select embodiments of the     present invention five (5) points may be marked in a vertical line     on each end panel 17 at approximately one foot in from the joint     connecting the lateral panel 15. For a five (5) foot high cell 10,     the marks 81 are approximately ten (10) inches apart, starting at     ten (10) inches from the top of each end panel 17. -   6) Cutting a small hole at each of the marks 81 on the end panels 17     enables a suitable fastener well known in the art, such as a zip     tie, to be looped through each hole and either providing tabs 91 or     cutting a corresponding hole in one of the two matching gate     sections comprising the gate 31 to attach individually the gate     sections to the insides of the conventional soil-filled cell 10 to     create the modified cell 30. -   7) Joining each gate section to close the gate 31 by using an     appropriate fastener such as a joining spring 13. In select     embodiments of the present invention this creates a 1′×3.5′×5′     quick-fill section 42 that reduces fill time to yield an effective     barrier against small arms fire. -   8) In select embodiments of the present invention using a vertical     rod provided in conventional soil-filled barriers, such as Hesco Mil     1 Bastions®, to connect multiple cells 10, cutting a 16″ piece from     the rod and bending each end to form a support member 41 (FIG. 4)     approximately 12″ long with loop-shaped hooks on each end. Cutting     small holes in each of the gate 31 and the center of the lateral     panel 15, insert each end of the hooks of the support member 41 to     bridge from the center of the lateral panel 15 to the gate 31 to     prevent bulging of the quick-fill section 42 and to provide an     optimum opening for filling the quick-fill section 42.

In select embodiments of the present invention, when not in use, the individual sections of the gate 31 are pushed against their respective end panel 17 and the modified cell 30 is collapsed and may be opened up normally as shown in FIGS. 1 and 2. Alternatively, end panels 17 may be used to fabricate gates 31 in field expedient scenarios, especially if material for making gates 31 is scarce. In select embodiments of the present invention, modified cells 30 may be factory made and fasteners, such as the tabs 91 (FIG. 9) or hook and loop fasteners, and the like, may be provided in the production model for ease of fastening.

Refer to FIG. 10 showing users filling the quick-fill section 42 from the outside (exposed) of the cells 30. This side of the barrier line may be presented as the hostile side as shown in FIG. 11. Alternatively, as shown prepared for testing in FIG. 12, the empty side of the barrier line may be placed as the hostile side. Both alternatives have inherent advantages. The empty side being presented as the hostile side permits the user to easily fill the quick-fill sections from outside the cell 30 while being mostly hidden from view. Alternatively, the quick-fill section 42 may be presented as the hostile side but the user may not wish to fill it from outside the cell 30 since it would be clearly exposed to possible hostile threats. The inside of each cell 30 would need to be accessed either by removing a spring attachment 13 at one corner of the lateral panel 15 at the back (friendly side) or by lifting the cell 30 and having the user with a shovel slide under the cell 30 to fill the quick-fill section 42 from within the cell 30 itself.

Testing was undertaken with various firearms of different calibers and bullet types fired from a distance of 15′ to achieve maximum velocity. Results are shown in Table 1.

TABLE 1 Ammunition and Measured Velocity Test Velocities and Rate of Fire Velocity Ammunition (ft/s) AK-47 7.62 × 39 Ball 2288 AK-47 7.62 × 39 Ball 2308 AK-47 7.62 × 39 Ball 2312 AK-47 7.62 × 39 Ball 2287 AK-47 7.62 × 39 Ball 2359 AK-47 7.62 × 39 API 2337 AK-47 7.62 × 39 API 2336 AK-47 7.62 × 39 API 2339 AK-47 7.62 × 39 API 2336 AK-47 7.62 × 39 API 2326 Dragunov 7.62 × 54 API 2646 Dragunov 7.62 × 54 API 2626 Dragunov 7.62 × 54 API 2650 Dragunov 7.62 × 54 API 2596 M240 5 round burst 2797 7.62 × 51 NATO M80 Ball M240 5 round burst 2813 7.62 × 51 NATO M80 Ball

Cardboard witness panels (not shown separately) were installed on the friendly (non-impact) side of the cells 30 of the test setup as shown in FIG. 12 with black dots painted as aiming points. The witness panels had no indentations, nor did any projectiles penetrate the material (fabric) liner on the friendly side of the cells 30. Impact holes on the hostile side of the gates 31 were taped to minimize loss of sand during testing to maintain test conditions the same from the beginning to the end of the testing.

Table 2 provides a summary of the ammunition used in additional testing. None of the ammunition was able to penetrate 12 inches of sand as filled in a quick-fill section 42 of a modified cell 30.

TABLE 2 Cartridge Caliber and Type Tested Caliber Type 5.56 M193 Ball 5.56 mm M855 AP 7.62 × 51 mm M80 Ball 7.62 × 39 mm Ball 7.62 × 39 mm AP (7.62 × 63 mm) M2 Ball (7.62 × 63 mm) M2 AP

The abstract of the disclosure is provided to comply with the rules requiring an abstract that will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. (37 CFR §1.72(b)). Any advantages and benefits described may not apply to all embodiments of the invention.

While the invention has been described in terms of some of its embodiments, those skilled in the art will recognize that the invention can be practiced with modifications within the spirit and scope of the appended claims. For example, although the system is described in specific examples for quickly filling sand-filled barriers used to withstand small arms fire, it may be used for producing any type of barrier that may be useful for protection from airborne projectiles in such diverse applications as, adverse weather, mining hazards, industrial processes, local security, and the like. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. Thus, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting, and the invention should be defined only in accordance with the following claims and their equivalents. 

What is claimed is:
 1. An improved soil-filled revetment cell structure of interconnected panels, said improved cell structure comprising: a.) first and second end panels; b.) a friendly side panel; and c.) a hostile side panel; wherein said cell structure is transformable between a flattened condition and an erected condition, wherein said erected condition of said cell structure defines an upright cell having corners with said first and second end panels forming first and second end walls and said friendly and hostile side panels forming friendly and hostile side walls, said end walls and said side walls being interconnected at said cell corners; said side panels and said end panels are pivotally interconnected in both said flattened condition and said erected condition so as to allow said cage structure to be transformed from said flattened condition to said erected condition by relatively pivoting said end panels and said side panels; wherein each said side panel is made up of pivotally interconnected side panel sections which lie folded in said flattened condition, and d.) an interior panel section oriented in a plane substantially parallel to said side panels and between said side panels and comprised of at least two connectable gates, a first of said at least two gates pivotally interconnected to said first end panel and a second of said at least two gates pivotally interconnected to said second end panel, said interior panel interconnections to said end panels being at a distance closer to said friendly side panel than to said hostile side panel and, when said at least two connectable gates are in a connected condition, defining a friendly side section volume and a hostile side section volume of the cell, said friendly side section having a lesser volume than the hostile side section.
 2. The cell structure according to claim 1, further comprising a spacer element connecting said interior panel said friendly side panel.
 3. The cell structure according to claim 1, wherein said friendly side volume is filled with dirt or sand.
 4. A revetment wall formed from a plurality of the cells of claim
 3. 5. The revetment wall of claim 4 wherein the end panels are shared between adjacent cells.
 6. The revetment wall of claim 4 wherein the cell is field-assembled from a plurality of (n+1) cells supplied with no interior panels, and the interior panel is formed from pieces of a side panel from an (n+2) cell which is not used in said wall.
 7. The cell structure according to claim 1 wherein the distance between the friendly side panel and the interior panel is at least one foot.
 8. The cell structure according to claim 1 wherein the distance between the friendly side panel and the interior panel is approximately one foot.
 9. The cell structure according to claim 1 wherein the friendly side section takes at least 65% less time to shovel fill than the entire volume of the cell, that is, the volumes of both the friendly side and the hostile side.
 10. The cell structure according to claim 9 providing ballistic protection from a weapon selected from the group consisting of an AK-47 (7.62×39), a 7.62×63 sniper rifle, the Dragunov sniper rifle (7.62×54) and the FN M240 machine gun (7.62×51NATO).
 11. A method of constructing an improved soil-filled revetment cell structure of interconnected panels, said improved cell structure comprising: a.) providing first and second end panels; b.) providing a friendly side panel; and c.) providing a hostile side panel; wherein said cell structure is transformable between a flattened condition and an erected condition, wherein said erected condition of said cell structure defines an upright cell having corners with said first and second end panels forming first and second end walls and said friendly and hostile side panels forming friendly and hostile side walls, said end walls and said side walls being interconnected at said cell corners; said side panels and said end panels are pivotally interconnected in both said flattened condition and said erected condition so as to allow said cage structure to be transformed from said flattened condition to said erected condition by relatively pivoting said end panels and said side panels, wherein each said side panel is made up of pivotally interconnected side panel sections which lie folded in said flattened condition, and taking said transported cell and placing said transported cell into an erected condition; d.) providing an interior panel section oriented in a plane substantially parallel to said side panels and between said side panels and comprised of at least two connectable gates, connecting a first of said at least two gates pivotally to said first end panel and connecting a second of said at least two gates pivotally to said second end panel, said interior panel interconnections to said end panels being at a distance closer to said friendly side panel than to said hostile side panel and, when said at least two connectable gates are in a connected condition, defining a friendly side section volume and a hostile side section volume of the cell, said friendly side section having a lesser volume than the hostile side section; and connecting said at least two gates to form said interior panel section.
 12. The method according to claim 11, further comprising the step of using a spacer element to connect said interior panel said friendly side panel.
 13. The method according to claim 11, further comprising the step of filling said friendly side volume with dirt or sand.
 14. A method of forming a revetment wall by placing a plurality of the cells of claim 13 together in an end to end relationship.
 15. The method of claim 14 wherein the end panels are shared between adjacent cells.
 16. The method of claim 14 wherein the cell is field-assembled from a plurality of (n+1) cells supplied with no interior panels, and the interior panel is provided by taking pieces of a side panel from an (n+2) cell which is not used in said wall.
 17. The method according to claim 11 wherein the distance between the friendly side panel and the interior panel is at least one foot.
 18. The method according to claim 11 wherein the distance between the friendly side panel and the interior panel is approximately one foot.
 19. The method according to claim 11 wherein the friendly side section of a cell takes at least 65% less time to shovel fill than the entire volume of said cell, that is, the volumes of both the friendly side and the hostile side.
 20. The method according to claim 19 wherein said cell provides ballistic protection from a weapon selected from the group consisting of an AK-47 (7.62×39), a 7.62×63 sniper rifle, the Dragunov sniper rifle (7.62×54) and the FN M240 machine gun (7.62×51NATO). 